An organic photoreceptor containing an organic photoconductive material is most widely employed in the electrophotography. While the organic photoreceptor has such advantages that it is easy to develop materials corresponding to various exposing light source from visible to infrared light, materials without environmental contamination can be selected, and manufacturing cost is low, in comparison with the other photoreceptor, there is a problem that mechanical strength is weak and it is liable to generate deterioration or damage on a surface of the photoreceptor during a plenty sheets of copying or printing.
It has been demanded to reduce an abrasion due to scraping by cleaning blade etc., so as to improve the durability of the organic photoreceptor. For this purpose technology to provide a protecting layer with high mechanical strength on the photoreceptor has been tried. For example, the patent document No. 1 reports that colloidal silica containing hardenable siloxane resin is used for the protective layer of the photoreceptor. The colloidal silica containing hardenable siloxane resin has high moisture absorbing characteristics both in hardenable resin having siloxane bond (Si—O—Si bond) and colloidal silica, and therefore, electric resistivity of the protective layer is liable to lower and causing image blur or image flow.
The other patent documents Nos. 2 and 3 report a protective layer is composed of hardenable resin obtained by reacting a metal oxide having a polymerizable unsaturated group with an organic compound having a reactive group capable of forming chemical bonding with the polymerizable unsaturated group, and it is successful in obtaining anti-abrasion property compatible to amorphous silicon. However, the problems of image blur or image flow under the condition of high temperature and high humidity is not dissolved sufficiently, and compatibility to the hardness can not be accomplished sufficiently.    Patent document No. 1: JP-A H06-118681    Patent document No. 2: JP-A H11-095473    Patent document No. 3: JP-A H11-095474